This invention relates to a spool. In particular, the invention concerns a spool for a swimming pool cover or for a shade cover, for allowing the cover to be unwound from the spool and returned to a retracted wound position relative to the spool.
The invention will be described by way of example with reference to its use with a cover for a swimming pool and with a cover for providing shade. It should be appreciated that this is by way of example only and that the spool may be used with a web or cover intended for other purposes.
Where swimming pools are heated, covers are used and arranged to extend over the surface of the pool to retain heat within the water when the pool is not in use. The cover is mounted on a spool which allows the cover to be wound onto the spool in a retracted position when the pool is in use and allows the cover to be unwound from the spool so that it extends over the pool when the pool is not in use.
Unwinding and retracting of the cover relative to the spool may be achieved in a manual fashion or the spool may be driven by a motor. Manual operation of such spools is tedious. Motor driven operation is preferred but has its disadvantages. A source of electric power needs to be available to drive the spool and having electrical appliances near wet areas such as swimming pool surrounds or exposed to the elements is undesirable. In addition, motor driven spools of this type are relatively expensive. Likewise, spools used to extend and retract shade covers have similar disadvantages.
It is an object of the present invention to provide a spool for covers or the like which at least minimises the disadvantages referred to above.
According to a first aspect of the invention, there is provided a spool for covers, the spool having a roller assembly, at least one cover attached to the roller assembly and adapted to be wound onto the roller assembly and unwound from the assembly, the roller assembly including a rubber member that when viewed in transverse cross-section is substantially rectangular in shape and two opposing sides of the rectangle are notched, which member may be tensioned when the cover is unwound from the spool.
Preferably, the notches in the rubber member are V-shaped.
As the cover is unwound from the spool, the rubber member may generate torque that initially increases at a rapid rate, following which the amount of torque generated may drop to a rate of increase lower than that initially until the cover is in a fully extended position.
Preferably, the rubber member comprises a rubber strip that extends along the roller assembly. The rubber member may be pre-tensioned such that when the cover is fully retracted the rubber member is still under tension. Preferably the member comprises natural rubber and has a Shore hardness of 50.
The roller assembly may include a sleeve about which the cover may be wound. The rubber member may be located within the sleeve. The roller assembly may have at least one handwheel.
More than one cover may be attachable to the roller assembly. For instance, two covers may be attached to the roller assembly, at opposing sides of the sleeve.
The spool may have a releasable locking mechanism operable for retaining the cover in a desired unwound position against the tension of the rubber member. When the locking mechanism has been released, the cover may be wound onto the roller assembly.
The roller assembly may have opposed shafts securely fixed to opposed ends of the rubber member. One of these shafts may be mounted for rotation and the other may be received by the locking mechanism and may selectively be held against rotation by the locking mechanism or released by the locking mechanism to allow it to rotate.
The locking mechanism may include a ratchet and pawl arrangement. The pawl or pawls may be carried by the roller assembly and the ratchet may be carried by the shaft that is received by the locking mechanism. Alternately, the shaft that is received by the locking mechanism may be fixed to a hub having at least one aperture, and the locking mechanism may include a locating pin that is located relative to the hub, and the locating pin may be moved to engage the aperture.
The spool may be carried by a stand consisting of two or more spaced stand members. Each stand member may receive an end of a respective said opposed shaft.
The spool may be used with a pool cover. The spool may be used with a shade cover.
According to a second aspect of the invention, there is provided a shade cover assembly having:
a roller assembly, at least one cover attached to the roller assembly and adapted to be wound onto the roller assembly and unwound from the assembly, the roller assembly including a rubber member that when viewed in transverse cross-section is substantially rectangular in shape and two opposing sides of the rectangle are notched, which member may be tensioned when the cover is unwound from the spool; and
a plurality of substantially vertical stand members, wherein the spool is adjustably mounted to two of the members, and when the cover is extended, a free end of the cover may be adjustably mounted to at least one other member, wherein the spool and the free end of the cover may be raised or lowered relative to the members independently of one another.